1 . 某校数学兴趣小组有14位同学,他们组成了n个不同的课题组.每个课题组有6位同学,每位同学至少参加2个课题组,且任意两个课题组至多有2位共同的同学,求n的最大值.
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2 . 已知
,
,…,
是集合
的n个非空子集,如果对于任意的i,
,均有
,则n的最大值为___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9721059d158853671eaf19e39769b13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd8db4b168ddbcba90ac9b31d36a0432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cfeacc29e6a61c5b3b4e439c0a91df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64e11e77f3276edde5c0a9f2057beb44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a42daf2970136f21f3e5b3b2f96fe44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac30abcc83eecff9e2cb8dabc1d10ac8.png)
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解题方法
3 . 设集合
中至少有两个元素,且
满足:①对于任意
,若
,都有
;②对于任意
,若
,则
;则集合
可以是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/480c2a8506904652c82020bd72b59d78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4c6b58a981ba3174c8771fee390914c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76b7cfa60c9af4cfb8de5c8fdf1c4d9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/165f629337523e8d4382a0dfb0f794ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c0bc161ae87e18977d23ed753ea786b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b678bfcaf23d6b8a7f73f35d03c07897.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d035fd92184fb215da52254d57b9b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88042bda196aa8fb3ec6b65f249ce519.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44c4dce884147e801b50675b9c0714e5.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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4 . 对集合
(
),若对于任何的
不能整除
的任何一个非空子集的元素和,则称
是“好集”(
表示集合
除去元素
后的集合).
(1)若
是好集,求
的最小值
;
(2)证明:集合
不是好集,其中,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2344e0bdfa0fc62283a93d4fe67ea89e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b58b34e73f045f54f9b2ee7daad5fc98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5805e7b270434d58308046727e963ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5805e7b270434d58308046727e963ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3bb14e6163867fe0acaffbb05ad2f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d7e9f86738335a22298559db41037a4.png)
(2)证明:集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ff7ed34e0562a4542fe4b860753995f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4806dc988e47163bc2178983196b9bff.png)
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